Weiser, Idaho 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

200
FXUS65 KBOI 200400
AFDBOI

Area Forecast Discussion
National Weather Service Boise ID
900 PM MST Fri Dec 19 2025

.DISCUSSION...Dry, cool air has moved in behind the cold front
currently stationed over the Magic Valley-southern Owyhee
County. The cold front is continuing to bring breezy winds and
light rain and snow above 5500-6000 feet over areas near the
ID-NV border, but this will taper off of overnight with limited
additional accumulation. Clear skies and light winds in valleys
will allow for fog formation overnight. Low visibility will be
the primary hazard during the early morning hours, with fog
mixing out by mid morning in most locations. Mostly dry
conditions are anticipated tomorrow, with Updated the forecast
to add fog and increase snow levels this evening, with
temperatures slow to cool behind the frontal passage in the
Magic Valley.

&&

.AVIATION...Precipitation continuing in SW-Idaho near KTWF/KJER.
Primarily rain showers through Sat/05z with lingering rain/snow
showers near KTWF after. MVFR/LIFR in precip. Precip ending area-
wide late Sat morning. Patchy valley fog overnight, mtns obscured.
Surface winds: Becoming variable up to 12kt overnight. Winds aloft
at 10kft MSL: W-NW 40-60kt.

KBOI...VFR. A 10% chance of fog/low stratus between 06z-12z. Surface
winds: NW 6-10 kt this evening, becoming variable and then SE
overnight into Saturday morning.

Sunday Outlook...Widespread rain/snow Sunday. Snow levels 3k-5kft
MSL to north, 6k-7kft to south, rising throughout day. Mtns
obscured. Surface winds: SW-SE 5-15 kt Saturday. SW-SE 10-20 kt with
gusts to 20-30 kt Sunday.

&&

.PREV DISCUSSION...
SHORT TERM...Tonight through Sunday night...A cold front will
continue to push through southern Idaho and far southeastern
Oregon through this evening. Rain, mixing with or changing to
snow above 3000-4500 feet MSL, and gusty winds 30-45 mph will
accompany the front. Light snow accumulations of generally less
than 1 inch are possible in mountain valleys as snow levels
lower. Weak instability along the front will allow heavier
embedded showers to develop and a few rumbles of thunder will be
possible (10% chance). Gusty winds to 55 mph near the Nevada
border will subside behind the front.

A flat upper level ridge will bring one day of calm conditions
on Saturday, with only a 10-30% chance of snow showers confined
to near the Nevada border. Highs will be 10-15 degrees cooler
than today, which will still be up to 5 degrees above normal.
Winds will also be relatively light.

A deep trough off the coast will direct a subtropical plume of
moisture onshore into northern California and the Pacific
Northwest late Saturday night through Sunday. This will produce
widespread rain and snow across our area as a warm front lifts
north. Snow levels will start near valley floors, which may
allow light snow accumulations at lower elevations from Ontario
north to Baker City and the Upper Weiser River where cold air is
likely to remain trapped for longer. Snow levels will rise
through the day, reaching 5000-7000 feet by Sunday evening.
Moist southwest flow will keep precipitation going into Sunday
night. This event will bring light to moderate snow
accumulations in mountain valleys before changing over to rain,
with over a foot of snow on peaks above 6000-7000 feet. In the
valleys, 0.25-0.75 inch of rain is anticipated. Winds will once
again become breezy on Sunday.

LONG TERM...Monday through Friday...A digging trough off the
West Coast will keep the region under southwest flow aloft
through mid- week. This flow pattern will favor precipitation in
the mtns, while embedded waves bring periods of rain to the
valleys. Snow levels will rise Tue/Wed to between 5500-7500 feet
MSL as the southerly flow increases. Temperatures will again
reach 10-15 degrees above normal. Wednesday will see another
wave of deep moisture hit the Sierras, spilling into the
interior NW Wed night and Thursday. Snow levels on Christmas
will drop to between 4-6kft MSL with light to moderate
precipitation focused on the mountains. Most deterministic
guidance brings the trough onshore late Thur/Fri which will
further lower snow levels and increase precipitation chances
across all elevations. Liquid totals in the mtns will run
0.75-1.5 inches through the period with higher elevations (aoa
6kft MSL) seeing heavy wet snow (averaging 10:1 ratio). The
southerly flow will bring breezy conditions across open and
higher terrain of SE Oregon and mtns of SW Idaho Wed/Thur. And
after peaking on Wednesday, temperatures pull back to around 10
degrees above normal Thur/Fri.

&&

.BOI WATCHES/WARNINGS/ADVISORIES...
ID...None.
OR...None.

&&

$$

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DISCUSSION...SA
AVIATION.....NF
SHORT TERM...ST
LONG TERM....DG